HOME SEARCH STATUS FEEDBACK DOWNLOAD CONTACTS

INTERFACE
Bacteria
Acinetobacter
Aeromonas
Anaplasma
Bacillus
Bartonella
Bordetella
Brucella
Burkholderia
Campylobacter
Chlamydia
Clostridium
Corynebacterium
Coxiella
Enterococcus
Escherichia
Francisella
Haemophilus
Helicobacter
Klebsiella
Legionella
Listeria
Mycobacterium
Mycoplasma
Neisseria
Pseudomonas
Rickettsia
Salmonella
Shigella
Staphylococcus
Streptococcus
Vibrio
Yersinia
Links
dbTC
dbeCIS
DRodVir
DBatVir
TrED
ShiBASE
GenomeComp

Identified virulence factors of Corynebacterium: Adherence


CdiLAM  

Keywords: Adherence;
Characteristics:
The genus Corynebacterium is part of the phylogenetic group nocardioform actinomycetes. The cell wall of C. diphtheriae is composed of branched long-chain mycolic acids and other lipoglycans such as lipomannans (LM) and lipoarabinomannans (LAM).
Mannose-capped LAM (ManLAM) from M. tuberculosis may facilitate bacterial adherence to alveolar macrophages, particularly to mannose receptors and display immunomodulatory properties.
Structure features:
The key structural features of CdiLAM are a linear α-1-6-mannan with side chains containing 2-linked α-D-Manp and 4-linked α-D-Araf residues.
Functions:
An adhesin of C. diphtheriae in initial step of infection to human respiratory epithelial cells.
References:
Moreira LO, et al., 2008. Novel lipoarabinomannan-like lipoglycan (CdiLAM) contributes to the adherence of Corynebacterium diphtheriae to epithelial cells. Arch Microbiol 190(5):521-30.


DIP0733  

Keywords: Adherence; MSCRAMMs; Invasion;
Structure features:
Composed of seven transmembrane helices and a hydrophilic region.
C-terminal coiled-coil domain is important for the binding to Type I collagen and fibrinogen.
Functions:
A multi-functional VF involved in adhesion, invasion of epithelial cells and induction of apoptosis.
Mechanism:
Binds to extracellular matrix proteins such as type I collagen, fibronectin and human plasma fibrinogen.
References:
Sabbadini PS, et al., 2012. Corynebacterium diphtheriae 67-72p hemagglutinin, characterized as the protein DIP0733, contributes to invasion and induction of apoptosis in HEp-2 cells. Microb Pathog 52(3):165-76.
Antunes CA, et al., 2015. Characterization of DIP0733, a multi-functional virulence factor of Corynebacterium diphtheriae. Microbiology (Reading) 161(Pt 3):639-47.
Weerasekera D, et al., 2018. The C-terminal coiled-coil domain of Corynebacterium diphtheriae DIP0733 is crucial for interaction with epithelial cells and pathogenicity in invertebrate animal model systems. BMC Microbiol 18(1):106.


DIP1281  

Keywords: Adherence; Invasion;
Characteristics:
Surface-associated protein belongs to NlpC/P60 family.
Functions:
Involved in cell surface organization, adhesion and internalization in epithelial cells.
References:
Ott L, et al., 2010. Corynebacterium diphtheriae invasion-associated protein (DIP1281) is involved in cell surface organization, adhesion and internalization in epithelial cells. BMC Microbiol 10(2):0.


DIP1621  

Keywords: Adherence;
Characteristics:
Surface-associated protein belongs to NlpC/P60 family.
Functions:
Play a role in adhesion to epithelial cells.
References:
Kolodkina V, et al., 2011. Identification of Corynebacterium diphtheriae gene involved in adherence to epithelial cells. Infect Genet Evol 11(2):518-21.


DIP2093  

Keywords: Adherence; MSCRAMMs;
Structure features:
Structural similarity to SdrD protein from S. aureus, which plays an important role in the adherence of S. aureus to the ECM and in biofilm formation.
Functions:
Involved in binding to Type I collagen and host colonization.
References:
Peixoto RS, et al., 2017. Functional characterization of the collagen-binding protein DIP2093 and its influence on host-pathogen interaction and arthritogenic potential of Corynebacterium diphtheriae. Microbiology (Reading) 163:692-701.


SpaA-, SpaD- and SpaH-type pili  

Related genes: spaA; spaB; spaC; spaD; spaE; spaF; spaG; spaH; spaI;
Keywords: Adherence; Sortase-assembled pili;
Characteristics:
The presence of pili has been for many years the hallmark of Gram-negative bacteria. However, in several Gram-positive microorganisms, fimbrial structures have been described..
In C. diphtheriae, the pili are generated by the sortase machinery. The sortase-mediated export of pilin subunits seems to exist in other pathogenic species such as Clostridium perfringens, Actinomyces naeslundii, Streptococcus agalactiae, Streptococcus mutans, and Streptococcus pneumoniae..
Sortase is a cysteine transpeptidase conserved in all Gram-positive bacterial genomes. Sortase cleaves pilin precursors at the conserved LPXTG motif between threonine and glycine and tethers the threonine carboxyl group of the precursor protein to the amino group of cell wall cross-bridges within the lipid II precursor, or to the amino group of the conserved pilin motif within the surface protein precursor. The latter reaction leads to the formation of pilus fibres on the bacterial surface.
Structure features:
C. diphtheriae assembles on its surface three distinct pilus structures, designated as SpaA-, SpaD- and SpaH-type pili (Spa for sortase-meidated pilus assembly).
All three pilus types have similar components, a major pilin subunit and two minor pilus proteins. For example, the SpaA-type pilus is composed of a major pilin subunit SpaA forming the pilus shaft, a possible tip protein SpaC and a minor pilin SpaB decorating along the pilus shaft.
Figures:
a) Three gene clusters in the chromosome of C. diphtheriae NCTC 13129 that encode sortase genes and the sortase-mediated pilus assembly genes (Reproduced from: Mandlik A, et al., 2007. Corynebacterium diphtheriae employs specific minor pilins to target human pharyngeal epithelial cells. Mol Microbiol 64(1):111-124.)


b) Model for sortase-mediated pilus polymerization in C. diphtheriae. Pilin subunits are typical sortase substrates, containing an N-terminal signal peptide (SP) that promotes secretion through the Sec system and a C-terminal cell wall sorting signal, typically positioned at the C-terminal end of surface protein precursors and is composed of a conserved LPXTG motif, followed by a hydrophobic domain and a positively charged tail.sortase is a transpeptidase that cleaves sorting signals and links the C-terminus of surface proteins via an amide bond to the peptidoglycan cross-bridge. Sortase activity requires a conserved cysteine residue of the sortase signature motifLXTC and a conserved histidine. Cysteine functions as a nucleophile, whereas histidine is presumed to function as a base for the transpeptidation reaction. SpaC is thought to be the first subunit to be incorporated into pili. The sortase-SpaC acyl intermediate may be attacked by the free amino group of a conserved lysine residue (K) present in the pilin motif of SpaA. The SpaA sorting signal would be in turn cleaved by sortase and linked to the lysine of a second SpaA pilin subunit. The remainder of the filament may then assemble by a sequence of similar transpeptidation reactions, and the polymerized pili may then be transferred to cell wall cross bridges for immobilization in the bacterial envelope (Reproduced from: Ton-That H, Schneewind O, 2004. Assembly of pili in Gram-positive bacteria. Trends Microbiol 12(5):228-234.)

Functions:
Involved in corynebacterial attachment to host tissues.
Mechanism:
SpaA-type pilus is sufficient for the specific adherence of corynebacteria to human pharyngeal epithelial cells. The minor pilins SpaB or SpaC protein bind specifically to pharyngeal cells. The function of SpaD-type and SpaH-type pili remains unknown.
References:
Ton-That H, Schneewind O, 2003. Assembly of pili on the surface of Corynebacterium diphtheriae. Mol Microbiol 50(4):1429-1438.
Ton-That H, Schneewind O, 2004. Assembly of pili in Gram-positive bacteria. Trends Microbiol 12(5):228-234.
Ton-That H, et al., 2004. Sortases and pilin elements involved in pilus assembly of Corynebacterium diphtheriae. Mol Microbiol 53(1):251-261.
Gaspar AH, Ton-That H, 2006. Assembly of distinct pilus structures on the surface of Corynebacterium diphtheriae. J Bacteriol 188(4):1526-1533.
Swierczynski A, Ton-That H, 2006. Type III pilus of corynebacteria: Pilus length is determined by the level of its major pilin subunit. J Bacteriol 188(17):6318-6325.
Mandlik A, et al., 2007. Corynebacterium diphtheriae employs specific minor pilins to target human pharyngeal epithelial cells. Mol Microbiol 64(1):111-124.
Kang HJ, et al., 2009. The Corynebacterium diphtheriae shaft pilin SpaA is built of tandem Ig-like modules with stabilizing isopeptide and disulfide bonds. Proc. Natl. Acad. Sci. USA. 106(40):16967-16971.
Chang C, et al., 2011. Cell surface display of minor pilin adhesins in the form of a simple heterodimeric assembly in Corynebacterium diphtheriae. Mol. Micriobiol. 79(5):1236-1247.








Back to Top Enzyme
Back to Top Next